Developed by athletes, for athletes. Developed by an Ironman Triathlete and a 24-time marathoner, Yurbuds solve the problem athletes face wearing earphones. They don't hurt, and they are guaranteed to never fall out. Avid triathlete Seth Burgett, CEO of Yurbuds came up with the award-winning idea for custom fit earbud enhancers while participating in an Ironman competition. Yurbuds Earbud Enhancers were created for the human ear by athletes, audiologists, and engineers to stay in place, avoid pressure points, and provide a pain-free listening experience. Endure is a great option for fitness enthusiasts who prefer a sport earphone that provides behind the ear support. Yurbuds has created these with our patented twist-lock design plus the extra peace of mind offered by the earloops. Just like our personalized enhancers, the earloops are made from a soft, comfortable silicone, so that they never cause discomfort. They are flexible and securely wrap your ears rather than hang heavily. Features Twist Lock Technology - Yurbuds are the number #1 sport earphone because they perform like no other. Yurbuds Twist Lock into place for a secure fit that never falls out even under the most intense workout conditions. Ultra Soft Comfort Fit - Yurbuds are ergonomically designed to avoid nerve rich areas of the ear. Made with medical grade silicone, Yurbuds are ultra soft and comfortable for hours on end. Exceptional Sound Quality - Clinically proven acoustics for deeper, richer sound. Performance Enhancing - Works under most vigorous conditions. Sweat & Water Resistance - Perfect for training in any condition. Universal Compatibility - Supporting an industry standard 3.5mm (1/8") gold plated stereo mini-plug for wide-ranging compatibility. Specifications Driver Type: 13mm Dynamic Frequency Response: 20-20,000Hz Sensitivity: 110 dB/V @ 1 kHz Impedance: 32 ohms Interface: 3.5mm Stereo Plug Cable: 1.2m (3.9ft) Fiber Re-Inforced Cable Weight: 28g (1 oz)